Nuclear transport: Run by Ran?
Nuclear transport: Run by Ran?
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DOI：
10.1086/301990
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发表时间：
1998-08-01
影响因子：
9.8
通讯作者：
Pu, RT
中科院分区：
文献类型：
--
作者：
Dasso, M;Pu, RT
A distinguishing feature of eukaryotic cells is the compartmentalization of their DNA within the nucleus. The sequestration of the genetic material away from the translational machinery and cytosolic proteins has at least two obvious but important implications: First, there must be a mechanism whereby the separate identities of the nucleus and cytosol are established and maintained within each cell cycle. The existence of such a mechanism was confirmed by the finding that many karyophilic proteins have nuclear localization sequences (NLS)(Gorlich and Mattaj 1996). NLS-bearing proteins enter the nucleus through a process that can be subdivided into at least two steps: a receptor-mediated, energy-independent docking on the cytosolic face of the nuclear pore complex (NPC) and an energy-dependent translocation of the docked NLS-bearing protein (substrate) into the nucleus (Gorlich and Mattaj 1996). Second, it is clear that differential access of proteins to the nucleus may be used as an important regulatory step for signal-transduction pathways, cell-cycle control, or developmental processes. It frequently has been found that import of proteins into the nucleus is modulated at the level of substrate accessibility (eg, by posttranslational modification or dissociation from other proteins [Nigg 1997]). It is likely that the transport machinery itself is also regulated, although this has not yet been as clearly demonstrated.Recent advances in this field also have shown that the nuclear transport machinery is highly conserved. This conservation suggests that findings about nuclear transport mechanisms and their regulation in different experimental systems may be broadly applicable to diverse organisms, including humans. In this review, we will briefly discuss soluble proteins involved in nuclear transport, with a particular focus on Ran, a small GTPase that is essential for transport in all eukaryotic organisms. Because of the brevity of this review, our discussion of transport mechanisms will not be as comprehensive as
